Liquid delivery apparatus for tissue ablation

ABSTRACT

An apparatus for use in a tissue ablation procedure includes a base, a fluid delivery tube coupled to the base, a first lever rotatably coupled to the base, the first lever having a first end biased to press against a portion of the fluid delivery tube to thereby close a lumen within the fluid delivery tube, and a second end, and a securing mechanism for securing the base relative to an ablation device. An ablation system includes an ablation device having an electrode, a fluid delivery tube coupled to the ablation device, and a control for simultaneously activating the electrode and opening the fluid delivery tube. A method of performing tissue ablation includes operating a control to activate an electrode, thereby delivering ablation energy to target tissue, wherein the step of operating the control also causes fluid to be delivered to the target tissue.

FIELD

The field of the application relates to apparatus for delivery of fluidsfor enhancing thermal heating and ablation of the tissue.

BACKGROUND

Tissue may be destroyed, ablated, or otherwise treated using thermalenergy during various therapeutic procedures. Many forms of thermalenergy may be imparted to tissue, such as radio frequency electricalenergy, microwave electromagnetic energy, laser energy, acoustic energy,or thermal conduction.

In particular, radio frequency ablation (RFA) may be used to treatpatients with tissue anomalies, such as liver anomalies and many primarycancers, such as cancers of the stomach, bowel, pancreas, kidney andlung. RFA treatment involves the destroying undesirable cells bygenerating heat through agitation caused by the application ofalternating electrical current (radio frequency energy) through thetissue.

Various electrosurgical instruments have been suggested for thispurpose. For example, published PCT application WO 96/29946 discloseselectrosurgical probes that include a number of independent wireelectrodes that may be extended into tissue from the distal end of acannula. The electrodes may be energized in a monopolar or bipolarmanner to heat and necrose a target tissue region. Such probes have beensuggested for treating tumors within organs, such as the liver, kidney,pancreas, stomach, and spleen.

To enhance heating and necrosis, saline may be injected into the targetregion before delivering electrical energy. Generally, this involvesadvancing a needle from a syringe into the tissue before or afteradvancing the electrodes from an electrosurgical probe into the targetregion. Saline may be delivered from the syringe into the tissue throughthe needle, and then the electrodes may be energized to deliver RFenergy and necrose tissue within the target region. Alternatively,saline may be delivered through a lumen in one or more of the wireelectrodes. Saline may increase heating of the tissue, therebyincreasing the size of the resulting lesion, as compared to energizingthe electrodes without saline.

In existing ablation devices that have fluid delivery capability, theactivation of the ablation electrode is controlled by a first control,such as a button, and the delivery of the fluid is controlled by asecond control, such as a plunger. However, such device is cumbersome touse because it requires a physician to perform two separates steps,i.e., a first step to operate the ablation device, and a second step tooperate the fluid delivery mechanism.

In addition, some existing ablation devices do not have a fluid deliverycapability. In such cases, a physician will have to find another devicefor delivering saline. For example, the physician may use a separatesyringe for delivering saline. However, where a separate syringe is usedto deliver the saline, the syringe and the ablation device requireseparate handling by the physician, thereby complicating the procedure.

SUMMARY

In accordance with some embodiments, an apparatus for use in a tissueablation procedure includes a base, a fluid delivery tube coupled to thebase, a first lever rotatably coupled to the base, the first leverhaving a first end biased to press against a portion of the fluiddelivery tube to thereby close a lumen within the fluid delivery tube,and a second end, and a securing mechanism for securing the baserelative to an ablation device.

In accordance with other embodiments, an ablation system includes anablation device having an electrode, a fluid delivery tube coupled tothe ablation device, and a control for simultaneously activating theelectrode and opening the fluid delivery tube.

In accordance with other embodiments, a method of performing tissueablation includes operating a control to activate an electrode, therebydelivering ablation energy to target tissue, wherein the step ofoperating the control also causes fluid to be delivered to the targettissue.

Other aspects and features of the embodiments will be evident fromreading the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments of theapplication, in which similar elements are referred to by commonreference numerals. In order to better appreciate how advantages andobjects of various embodiments are obtained, a more particulardescription of the embodiments are illustrated in the accompanyingdrawings. Understanding that these drawings depict only typicalembodiments of the application and are not therefore to be consideredlimiting its scope, the embodiments will be described and explained withadditional specificity and detail through the use of the accompanyingdrawings.

FIG. 1A illustrates a fluid delivery apparatus in accordance with someembodiments;

FIG. 1B is a side view of the fluid delivery apparatus of FIG. 1A;

FIG. 2 illustrates the fluid delivery apparatus of FIG. 1A, showing theapparatus being secured to an ablation device in accordance with someembodiments;

FIG. 3 illustrates the fluid delivery apparatus of FIG. 1A, showing afirst lever being pressed;

FIG. 4 illustrates the fluid delivery apparatus of FIG. 1A, showing asecond lever being pressed;

FIG. 5 illustrates a fluid delivery apparatus in accordance with otherembodiments;

FIG. 6 illustrates a fluid delivery apparatus in accordance with otherembodiments; and

FIG. 7 illustrates an ablation device having a fluid delivery apparatusin accordance with other embodiments.

DESCRIPTION OF THE EMBODIMENTS

Various embodiments are described hereinafter with reference to thefigures. It should be noted that the figures are not drawn to scale andelements of similar structures or functions are represented by likereference numerals throughout the figures. An aspect, a feature, or anadvantage described in conjunction with a particular embodiment is notnecessarily limited to that embodiment and can be practiced in any otherembodiments described herein.

FIG. 1A illustrates a fluid delivery apparatus 10 configured to be usedwith an ablation device in accordance with some embodiments. Theapparatus 10 has a base 12, a first lever 14, a second lever 16, and afluid delivery tube 18. In the illustrated embodiments, the base 12 hasa planar configuration. However, the base 12 can have otherconfigurations in other embodiments. It should be noted that the word“base”, as used in this specification, refers to a structure to whichother components of the apparatus 10, such as the lever 14 or the tube18 may be coupled. As such, the base 12 needs not be in any particularposition relative to other components of the apparatus 10. For example,the base 12 needs not be located at a bottom of the apparatus 10.

The first lever 14 has a first end 20 for pressing against a portion ofthe fluid delivery tube 18, and a second end 22. Similarly, the secondlever 16 has a first end 24 for pressing against a portion of the fluiddelivery tube 18, and a second end 26. The first and the second levers14, 16 are rotatably coupled to the base 18 via a shaft 40. The fluiddelivery tube 18 has a distal end 50 and a proximal end 52, whichconnects to a fluid source, such as a bag of saline, a source ofconductive fluid, or other fluid sources.

FIG. 2 illustrates the fluid delivery apparatus 10 being used with anablation device 200 in accordance with some embodiments. The ablationdevice 200 includes a probe 202, an electrode 204 located at a distalend 206 of the probe 202, a first switch 208, and a second switch 210.The ablation device 200 may be any device that is configured to deliverenergy to heat tissue. For example, the ablation device 200 can be acautery pen. During use, the ablation device 200 is electrically coupledto a generator 220, e.g., a radio frequency (RF) generator, whichdelivers energy to the electrode 204. In some embodiments, the firstswitch 208 is configured such that when it is pressed, the electrode 204will be activated to deliver energy at a first energy level, and thesecond switch 210 is configured such that when it is pressed, theelectrode 204 will be activated to deliver energy a second energy level.For example, the first energy level may be that which is suitable forcutting tissue, and the second energy level may be that which issuitable for coagulating target area.

In the illustrated embodiments, the apparatus 10 includes a sleeve 230that fits over the distal end 206 of the ablation device 200, therebysecuring the apparatus 10 relative to the ablation device 200. Thesleeve 230 includes a distal opening 232 for allowing a portion of theablation device 200 to exit therethrough. As shown in the figure, thesleeve 230 has a shape that resembles a nosecone. In other embodiments,the sleeve 230 can have other shapes and configurations, depending onthe configuration of the ablation device 200 to which the apparatus 10is secured. When the fluid delivery apparatus 10 is secured to theablation device 200, the distal end 50 of the tube 18 is located next tothe electrode 204.

It should be noted that the manner in which the fluid delivery apparatus10 is secured to the ablation device 200 is not limited to the exampledescribed previously, and that the fluid delivery apparatus 10 can haveother securing mechanisms for securing to the ablation device 200 inother embodiments. For example, in other embodiments, the fluid deliveryapparatus 10 can include a strap that ties around a circumference of theablation device 200, a snap-on that mates with a portion of the ablationdevice 200, a tongue that mates with a groove on the ablation device200, or a double-sided adhesive tape, for securing itself to theablation device 200. In further embodiments, instead of having asecuring mechanism that allows the fluid delivery apparatus 10 to bedetachably secured to the ablation device 200, the securing mechanismcan be used to permanently secure the fluid delivery apparatus 10 to theablation device 200. For example, in other embodiments, the fluiddelivery apparatus 10 further includes a glue that can be appliedbetween the fluid delivery apparatus 10 and the ablation device 200,thereby permanently securing the fluid delivery apparatus 10 to theablation device 200.

As shown in FIGS. 1 and 2, the base 12 includes a first opening 42 and asecond opening 44 that correspond with the locations of the first andsecond switches 208, 210, respectively, of the ablation device 200. Assuch, when the fluid delivery apparatus 10 is secured to the ablationdevice 200, the first and the second switches 208, 210 extend at leastpartially into the first and the second openings 42, 44, respectively.The first lever 14 has a portion 28 for engaging with the first switch208, and the second lever 16 has a portion 30 for engaging with thesecond switch 210. In the illustrated embodiments, the portions 28, 30are each in a form of a protrusion that extends from a surface of thelevers 14,16, respectively. In other embodiments, the portions 28, 30can have other configurations.

In the illustrated embodiments, the levers 14, 16 are biased by springs240, 242, respectively, such that the respective first ends 20, 24 arepressed against portions of the fluid delivery tube 18. The levers 14,16 are located relative to each other in a side-by-side manner such thatthe first end 20 of the first lever 14 presses against half of a crosssection of the tube 18, and the first end 24 of the second lever 16presses against the other half of the cross section of the tube 18. Suchconfiguration allows the first end 20 to be moved apart from the tube 18to partially open the lumen of the tube 18, when the second end 22 ofthe first lever 14 is pressed towards the base 12 to engage the firstswitch 208 (FIG. 3). Such configuration also allows the first end 24 tobe moved apart from the tube 18 to partially open the lumen of the tube18, when the second end 26 of the second lever 16 is pressed towards thebase 12 to engage the second switch 210 (FIG. 4).

During use, a user can selectively press either the first lever 14 orthe second lever 16 to active the first switch 208 or the second switch210, respectively. For example, during a procedure, if a physicianwishes to cut tissue, the physician can press the second end 22 of thefirst lever 14 towards the base 12 until the portion 28 contacts andpresses the first switch 208. This in turn, activates the electrode 204to deliver energy for cutting tissue, and at the same time, opens thetube 18 to allow fluid, such as saline, to be delivered to the electrode204. In some cases, the fluid source 220 may be placed at an elevationthat is higher than the fluid delivery apparatus 10, thereby allowingfluid to be delivered by pressure induced under gravitational force.Alternatively, the fluid source 220 may be coupled to a pump fordelivering fluid. The delivered saline may couple electrical energy totissue. In some cases, the delivered saline also shrinks collagen,closes vessels, and stops bleeding at the target tissue which has beencut. The saline may also keep the electrode 204 surface cool (e.g., 100°C. or below). In some embodiments, the fluid delivery apparatus 10 isconfigured (e.g., by selecting an appropriate height for the protrusion28) such that the fluid delivery tube 18 will open just prior to theprotrusion 28 depressing the first switch 208. When the first lever 14is released, the first lever 14 will spring back to its initial position(due to the spring 240), thereby clamping the lumen of the tube 18closed and stopping the flow of saline.

Alternatively if a physician wishes to coagulate a target tissue, thephysician can press the second end 22 of the second lever 16 towards thebase 12 until the portion 30 contacts and presses the second switch 210.This in turn, activates the electrode 204 to deliver energy for tissuecoagulation, and at the same time, opens the tube 18 to allow fluid,such as saline, to be delivered to the electrode 204. The deliveredsaline may couple electrical energy to tissue. The saline may also keepthe electrode 204 surface cool. In some embodiments, the fluid deliveryapparatus 10 is configured (e.g., by selecting an appropriate height forthe protrusion 30) such that the fluid delivery tube 18 will open justprior to the protrusion 30 depressing the switch 210. When the secondlever 16 is released, the second lever 16 will spring back to itsinitial position (due to the spring 242), thereby clamping the lumen ofthe tube 18 closed and stopping the flow of saline.

As shown in the above embodiments, the fluid delivery apparatus 10 isadvantageous in that it allows a physician to activate the electrode 204and cause delivery of fluid by the use of one finger in a single step.As a result, the physician does not need to manipulate multiple controls(e.g., one for ablation, and another for fluid delivery), or to handlemultiple instruments (e.g., ablation device and syringe) during theablation process.

In the above embodiments, the first end 20 of the first lever 14 pressesagainst half of the delivery tube 18 and the first end 24 of the secondlever 16 presses against the other half of the delivery tube 18.Alternatively, the apparatus 20 can have two fluid delivery tubes 500,502 (FIG. 5). In such cases, the first end 20 of the first lever 14presses against the delivery tube 500, and the first end 24 of thesecond lever 16 presses against the delivery tube 502. In theillustrated embodiments, the delivery tubes 500, 502 join into a distaltube 504. During use, when the first lever 14 is pressed to engage thefirst switch 208 on the ablation device 200, the first end 20 is movedapart from the first delivery tube 500, thereby creating an unobstructedflow of fluid through the tube 500 and allowing fluid to be deliveredthrough the tube 500 and into the tube 504. The fluid exits from thedistal end of the tube 504 and onto the electrode 204. Similarly, whenthe second lever 16 is pressed to engage the second switch 210 on theablation device 200, the first end 24 is moved apart from the seconddelivery tube 502, thereby creating an unobstructed flow of fluidthrough the tube 502 and allowing fluid to deliver through the tube 502and into the tube 504. The fluid exits from the distal end of the tube504 and onto the electrode 204.

In further embodiments, the apparatus 10 does not include the distaltube 504 (FIG. 6). In such cases, the fluid exits from the distal end ofthe tube 500 or the tube 502, and onto the electrode 204.

In the above embodiments, the fluid delivery apparatus 10 has beendescribed as having two levers 14, 16. In other embodiments, the fluiddelivery apparatus 10 can have other numbers of levers. For example, thefluid delivery apparatus 10 can have one lever for engaging with onebutton, or more than two levers for engaging with more than twoswitches, on an ablation device.

Also, in the above embodiments, the fluid delivery apparatus 10 has beendescribed as having delivery tube(s) that deliver fluid from external ofthe electrode 204. In other embodiments, the delivery tube describedherein can be at least partially placed within the ablation device 200to thereby allow fluid to be delivered from within the electrode 204(FIG. 7). In such cases, the electrode 204 will have a plurality ofopenings or pores for allowing fluid delivered from the tube(s) to exittherethrough. For example, the electrode 204 can have a sinteredconfiguration (e.g., made from a plurality of particles connectedtogether).

In further embodiments,. the fluid delivery apparatus 10 can be builtwithin the ablation device 200 itself. For example, the first lever 14can be placed underneath the switch 208, and the second lever 16 can beplaced underneath the second switch 210. In other embodiments, insteadof, or in addition to, implementing the fluid delivery apparatus 10using mechanical components, the apparatus 10 can be implemented usingelectrical components.

For example, in some embodiments, the first switch 208 is electricallycoupled to a first positioner, which pushes a block against, or removesthe block from, at least a portion of the tube 18. The first switch 208is also coupled to the electrode 204 such that when the first switch 208is pressed, the electrode 204 will be activated to delivery energy at afirst energy level, and the block will move apart from the tube 18 toallow fluid to be delivered via the tube 18. When the first switch 208is released, the electrode 204 will stop delivering energy, and thepositioner will move the block towards the tube 18 to press against thetube 18, thereby stopping flow of fluid within the tube 18.

Similarly, the second switch 210 is electrically coupled to a positioner(which may be the same positioner associated with the first switch 208),which pushes a block against, or removes the block from, at least aportion of the tube 18. The second switch 210 is also coupled to theelectrode 204 such that when the second switch 210 is pressed, theelectrode 204 will be activated to deliver energy at a second energylevel, and the block will move apart from the tube 18 to allow fluid tobe delivered via the tube 18. When the second switch 210 is released,the electrode 204 will stop delivering energy, and the positioner willmove the block towards the tube 18 to press against the tube 18, therebystopping flow of fluid within the tube 18.

It should also be noted that the ablation device 200 with which thefluid delivery apparatus 10 can be used is not necessarily limited tothe configurations described previously, and that the ablation device200 can have other configurations in other embodiments. For example, inother embodiments, the ablation device 200 can have different shapesand/or sizes. Also, in other embodiments, instead of having oneelectrode 204 for delivering energy, the ablation device 200 can includea plurality of electrodes at the distal end of the probe 202. Further,instead of delivering heat energy, the ablation device 200 can deliveryother forms of energy in other embodiments. For example, in otherembodiments, the electrode 204 can be configured to deliver electricalenergy. In further embodiments, the ablation device 200 can include oneor more ultrasound transducers (for generating ultrasound energy), orone or more microwave energy generators (for generating microwaveenergy).

Thus, although several embodiments have been shown and described, itwould be apparent to those skilled in the art that many changes andmodifications may be made thereunto without the departing from the scopeof the invention, which is defined by the following claims and theirequivalents.

1. An apparatus for use in a tissue ablation procedure, comprising: abase; a fluid delivery tube coupled to the base; a first lever rotatablycoupled to the base, the first lever having a first end biased to pressagainst a portion of the fluid delivery tube to thereby close a lumenwithin the fluid delivery tube, and a second end; and a securingmechanism for securing the base relative to an ablation device.
 2. Theapparatus of claim 1, wherein the first lever is biased such that thefirst end presses against the portion of the fluid delivery tube whenthe second end is not being pressed.
 3. The apparatus of claim 1,wherein when the second end is positioned towards the base, the firstend becomes disengaged from the portion of the fluid delivery tube tothereby allow fluid to flow therethrough.
 4. The apparatus of claim 1,wherein the second end has a portion for engaging a switch on theablation device.
 5. The apparatus of claim 4, further comprising theablation device.
 6. The apparatus of claim 1, further comprising asecond lever rotatably coupled to the base.
 7. The apparatus of claim 6,wherein the first and the second levers are positioned in a side-by-sideconfiguration.
 8. The apparatus of claim 6, wherein the second lever hasa first end for pressing against another portion of the fluid deliverytube, and a second end.
 9. The apparatus of claim 8, wherein the secondend of the first lever has a first portion for engaging a first switchon an ablation device, and the second end of the second lever has asecond portion for engaging a second switch on the ablation device. 10.The apparatus of claim 9, further comprising the ablation device. 11.The apparatus of claim 6, further comprising a second fluid deliverytube, wherein the second lever has a first end for pressing against aportion of the second fluid delivery tube.
 12. The apparatus of claim11, wherein the fluid delivery tubes are in fluid communication witheach other.
 13. An ablation system, comprising: an ablation devicehaving an electrode; a fluid delivery tube coupled to the ablationdevice; and a control for simultaneously activating the electrode andopening the fluid delivery tube.
 14. The ablation system of claim 13,wherein the control includes a first lever.
 15. The ablation system ofclaim 14, wherein the first lever has a first end for pressing againstthe tube, and a second end having a portion for engaging a switch on theablation device.
 16. The ablation system of claim 14, wherein thecontrol includes a second lever, at least a portion of the first leverconfigured for engaging a first switch on the ablation device, at leasta portion of the second lever configured for engaging a second switch onthe ablation device.
 17. The ablation system of claim 14, wherein thefirst lever is biased to pressed against a portion of the fluid deliverytube.
 18. A method of performing tissue ablation, comprising: operatinga control to activate an electrode, thereby delivering ablation energyto target tissue; wherein the step of operating the control also causesfluid to be delivered to the target tissue.
 19. The method of claim 18,wherein the control is operated by pressing a lever to create anunobstructed flow of the fluid within a fluid delivery tube, and thelever is pressed until it engages a switch on an ablation device. 20.The method of claim 18, wherein the ablation energy is delivered via anelectrode, and the fluid is delivered from external to the electrode.21. The method of claim 18, wherein the ablation energy is delivered viaan electrode, and the fluid is delivered from internal to the electrode.